They might look more like candy, but these micro-capsules are rather more special than that. Their shiny shell allows CO2 to pass straight through — where it can be trapped by a liquid held in their core.
The little spheres are made up of a permeable polymer shell which holds a fluid with sodium carbonate in it. In areas of high CO2 concentration, the gas passes through the shell and into the liquid, where it reacts to form sodium bicarbonate — like baking soda. The capsules can then be heated to release pure CO2 in a controlled environment, where it can stored away, compressed or perhaps even reused. The capsules were described in a paper published in Nature, and it’s hoped that they could be used in environments like power stations, to provide safe and affordable capture of CO2 from emitted gasses. [Nature via The Conversation]